Toggle switch



April 29, 1.958 T. A. ANDREW TOGGLE SWITCH Filed Nov. 21. 1955 INVENTOR.Flo/m5 A. ANDREW TOGGLE SWITCH Thomas A. Andrew, Newport Beach, Calif.,assigner to `l'anco Corporation, Burbank, Calif., .a corporation ofCalifornia Application November 21, 1955, Serial No. 547,926

8 Claims. (Cl. 20G- 18) This invention relates to electrical controldevices and dicator -light for indicating the condition of the con-ltrolled mechanism. Generally, such switches comprise a pair of switchelements which are operated by the single operating lever. In order thatthe indicator light always accurately indicates the condition of thecontrolled mechanism, it is essential that these two switch elements,for controlling the mechanism and the light, be actuated substantiallysimultaneously. Moreover, to facilitate operation of the switch andassure proper positioning of its operating lever in either of itsextreme positions, movement or deiiection of the lever between theseextreme positions must be appreciable.

Switches for use in aircraft installations are subject to considerableshock and vibration during flight of the aircraft and, accordingly, itis essential to the reliability of the switches that they not besensitive or responsive to such vibrations and'shock, that is, thattheir contacts will remain closed under the most adverse conditions ofshock and vibration.

Accordingly, it may be stated as a primary object of this invention toprovide a toggle switch, intended primarily though not exclusively foruse in aircraft installation, which fulfills the above and otherrequirements.

Another object of the invention is the provision of a toggle switchembodying a pair of switch mechanisms which are substantiallysimultaneously actuated upon movement of the switch operatingleverbetween its extreme positions.

Yet another object of the invention is the provision of a toggle switchwherein the operating lever undergoes appreciable movement of deflectionbetween its extreme positions so as to insure proper positioning of thelever.

A further object of the invention is the provision of a toggleswitchwhose operation is substantially unaffected by an environment ofshock or vibration in which the switch may be used.

And still a further object of the invention is the provision of a toggleswitch whose operation involves a substantial mechanical advantage sothat maximum contact opening and closing forces may be exerted with aminimum force on the operating lever.

The invention may be best understood from the following detaileddescription thereof taken in conjunction .wanted States atent O Fiiceswitch operating lever being omitted for the sake of clarity; and

Fig. 4 is a view similar to Fig. 1 with the switch operat` ing levershown in its other extreme position.

Referring now to these drawings, the toggle switch of this inventioncomprises a hollow metallic casing 10 open at its upper end, twoopposite side walls of which casing are formed with rectangular tabs 11that are bent inwardly at right angles to the planes of the side wallsand have their inner'edges spaced as shown in Fig. l. Closing the upperend of the casing 10 is a cover plate 12 formed with a centralrectangular opening 13 and iixed in position as by being bolted to thetabs 11, as indicated at 14. Secured to the underside of this coverplate 12, in the space between the inner edges of tabs 11, are a pair ofplates 15 and 16 which are centrally formed with alined slots 17 and 1Sregistered with the opening i3 in the cover plate 12. The upper one 15'of the slotted plates has formed on its upper surface a rectangularraised portion 19 of a sizek and shape corresponding to and receivedwithin the opening 13 in the cover plate l2. The plates 15 and 16 aresecured in position as by rivets 20.

The opposite end walls of the slots 17 and 18 in the plates 15 and 16conform to segments of a circle as shown, and received in these slots isa generally diskshaped intermediate portion 21 of an operating lever 22.The arrangement is such that lever 22 is pivotally mounted in the plates15 and 16v for pivotal movement between the position it occupies in Fig.l and the position it occupies in Fig. 4.

Encircling a lower cylindrical portion 23 of lever 22 is a compressionspring 24 which bears at its upper end against an annular shoulder 25,adjacent the juncture of the cylindrical portion 23 and the disk-shapedportion 2i, and at its lower end against a sleeve 26 slidable on thelower end of the cylindrical portion 23. Sleeve 26 is retained forlimited axial sliding movementon the cylindrical portion 23 by pin andslot arrangement 2'7 and, has its lower end transversely slotted asshown at 2S. The furcations 29 defining therebetween the slot 28 havetheir lower edges rounded, as illustrated, and journaled on a pin 30fixed at opposite ends in the furcations 29 is a roller 3l the lowerportion of whose periphery projects somewhat beyond the curved endportions of the furcations.

Roller 3l bears on and is adapted to ride over a curved platen 32 of arocker 33. Rocker 33 further comprises a pair of flanges 34 which extenddownwardly from the side edges of platen 32 at an intermediate portionof the latter, these flanges straddling and slidably bearing against theouter side surfaces of a pair of generally triangular-shaped flanges 35on a bracket 36 xed by rivets 37 to the bottom wall of casing lli. Apivot pin 33 extends through flanges 34 and 55 and has its opposite endsshouldered, as indicated, for pivotally mounting the rocker 33 on thebracket 36.

From the description thus far it will be seen that roller 31 isresiliently urged into contact with the curved platen 32 by thecompression spring 24 and that said roller may be caused to move fromone end of the platen to the other end thereof by pivotal movement ofthe operating lever between the positions of Figs. l and 4. It will befurther apparent that so long as a roller 31 `bears on that halt of theplaten 32 to the left, as viewed in Fig, l, of a dead center lineextending through the pivotal axes of the rocker 33 and the operatinglever 22, compression spring 24 will act to maintain the rocker 33 inits pivotal position illustrated in Fig. l. Simultaneously with themovement of the roller 3l across that dead center line, by left handmovement of the operating lever from 4l) will be retained closed.

the positiony in Fig. lto that of Fig. 4, the rocker 33 ywill be snappedto its right hand pivotal position, illustrated in Fig. 4, by the actionof the biasing spring 24.

This pivotal movement of therocker`33isarranged tooperate a pair ofmicroswitches 39 and 40 in thefollowing-manner.

Each of the microswitches 39 and 40 comprises an actuating arm. 41vwhose upper. end is pivoted at 42 to the casing of its associatedmicroswitch and which is biased awayfromr its casing to normal positionby springs, not shown. These actuating arms 41 bear, at an intermediatepoint, against the outer ends of the operating plungers 43 of therespective microswitches so that the microswitches 39 and 40 will beopened and closed by movement of the pivotal arms 41 toward and awayfrom their respective microswitches, The lower extremities of theactuating arms 41 are narrowed as indicated at 44, Fig. 2, are bent to agenerally flat-bottom V configuration 45 with the flat bottoms 46 of thev-shaped portions being disposed in substantially parallel planes inposition to intersect, at substantially right angles, a line extendingthrough the pivotal axis of the rocker normal to said dead center lineextending through the pivotal axes of the rocker and actuating lever 22.Ex-

tending from opposite sides of the flanges 34 of the rocker 33 are apair of pins 47Y each of which extends axially to a position ofjuxtaposition of its free end portion with the V portions 45 of the arms41. The arrangement of these pins on the rocker 33 is such that when thelatter is in its left hand pivotal position, illustrated in Fig. 1, theleft hand one of the pins 47, as viewed in this figure, will have itscenter on the aforesaid line tending through the rocker pivotal axisnormal to the iiattened portion 46 of its respective operating arm 41and will bear against said flattened portion in a manner to maintain thecorresponding operating arm 41 depressed out of its normal position sothat, for example, if microswitch 40 is a normally open switch, it willbe in its closed condition when the rocker is in the position of Fig. l.The right hand one of the pins 47, as viewed in Fig. l, will, however,be disposed above said normal line extending through the rocker pivotalaxis and in the vicinity of the upper sloping sides of the V of itsrespective operating arm 41 so that the latter will be cleared to beretained in its normal position by its biasing spring.

Upon the aforedescribed left hand pivotal movement of L the operatinglever 22 from its position of Fig. l to its position of Fig. 4 to rockthe rocker 33 to its right hand pivotal position illustrated in Fig. 4,the right hand one of the pins 47 will ride into the flat bottom portion46 of its associated switch operating arm 41 to cam that switchoperating arm out of its normal position'l Simultaneously, the left handone of the pins 47, as viewed in the drawings, will be moved to aposition corresponding to that occupied by the right hand pin 47 in Fig.l so that the switch operating arm 41 associated with the left hand oneof the pins 47 will be permitted to return to its normal position underthe action of its biasing spring. Thus, assuming both switches to benormally open switches, switch 39 will, in the position of the operatinglever shown in Fig. l, be open while switch Upon movement of theoperating arm 22 to the position of Fig. 4, the rocker 33 will beysnapped from its left hand pivotal position, shown in Fig. l, to itsright hand pivotal position, shown in Fig. 4, to substantiallysimultaneously effect the closing of switch 39 and reopening of switch40.

Each of the switches 39 and 4t) may include a plurality of terminals 48for connection to the lead in the electrical circuit which they are tocontrol. Thus, switch 39 may be connected in a circuit, not shown,extending to a motor to be selectively operated, while switch 40 may beconnected in an energizing circuit, not shown, for an indicator lightfor indicating whether the motor control circuit' is' energized rordeenergized.

4 Fromtheforegoing. description. it willv be. apparent that the presentswitching arrangement provides for optimum reliability even underrelatively severe conditions of shock and vibration, as are found, forexample, in aircraft installations, inasmuch as appreciable deflectionof the operating lever 22 is required to operate the rocker from one ofits pivotal positions to its other pivotal position so that evensubstantial movement of the operating lever as the result of suchvibrations and shocks will not .produce accidental actuation of theswitch. This inse Ynears or non-responsiveness of the present switchingarrangement to an environment of shock or vibration is also aided by theon-center locking feature of the rocker 33 and its pins 47. Thus, withthe parts positioned as shown in Fig. 1, switch operating arm 41 ot'switch 4t) will be locked out of its normal position when thecorresponding pin 47 of the rocker is in oncenter relationship withrespect to the rocker pivotal axis, that is, when the center of said pin47 is on the aforesaid line extendingY through the rocker pivotal axisnormal to the flat' portion 46 of its respective switch arm 4l. Thus,for a limited angle of pivotall movement of the rocker, movement of theleft hand pin 47 will be substantially normal to the direction ofpivotal movement of its switch armr 41 andv substantially parallel tothe plane of the associated flat portion 46, and, accordingly, thecorresponding switch operating arm 41 will be retained out of its normalposition even during any slight pivotal movement of the rocker as aresult of the switching mechanism being subjected to vibrations andshocks. Shocks and vibrationswill not, therefore, result in fluctuatingof the switch contacts. It will be seen that the length of the platen32, over which the roller 31 moves between extreme positions of theoperating lever 22, accommodates appreciable movement of the operatinglever which is desirable for ease of operation and proper positioning ofthe lever. Moreover, the arcuate configuration of the platen 32 providesa' mechanical advantage, which, for example, may be made less by causingthe platen32 to conform more to a flat plane. This mechanical .advantageenables maximum closing forces to be exerted on switch operating arms 41with a minimum force applied to the operating lever 2.2. Due to the snapaction of the rocker 33 upon movement of the roller 31 past the deadcenter position during movement of theV operating lever 22 between itsextreme positions, substantially simultaneous operation of the switches39 and 40 is eected so that, for example, where one switch controls theoperation of a controlled mechanism and the other switch controls theenergization of an indicator light, the latter will always accuratelyindicate the condition of operation of the controlled mechanism. Thepresent switchingV arrangement renders it virtuallyv impossibletoaccidentally position the operating lever 22 in a central or neutral.position wherein both of the switches 39 and 40 would` be inthe samecondition.

From the foregoing description itv will be seen that there has beendescribed and illustrated a toggle switch which is fully capable ofattaining the objects and advantages heretofore set forth. While apreferred. embodiment of the invention has been illustrated anddcscribed, it will be apparent to those skilledf in. the art thatnumerous modifications in designV and arrangement of parts is possiblewithin the scope of the following claims.

I claim:

l. An electric switch, comprising: a support, a rocker pivotally mountedon said support, switch means mounted on said support and including apivotal actuating arm swingable about an axis spaced from andsubstantially paralleling the pivotal axis of the rocker, said armextending toward the latter axis and `being formed with arelativelyrshort, straight section extending substantially parallel to aiirst imaginary plane passing ,5 through said axes and extending toopposite sides of a second imaginary plane passing through said rockerpivotal axes normal to said first plane, an actuating-armengagingelement on said rocker rotatable into said second plane and engageablewith said straight section of the actuating arm when the rocker isrocked in one direction for retaining said arm in one operativeposition, said element being movable beyond one end of said section whenthe rocker is rocked in the opposite direction, the portion of said armadjacent said one end of the section being relieved to accommodateswinging of said arm in theA direction of said element to a secondoperative position when said element is located beyond said one end ofthe section, said switch means including yieldable means biasing saidarm in said latter direction, and handle means engageable with saidrocker for rocking the latter in opposite directions.

2. The subject matter of claim 1 wherein said straight section is olsettoward said element in substantially spaced parallel relationship to theremainder of the arm, and said arm is formed with an inclined section atsaid one end of the straight section forming a cam surface engageableIby said element upon rocking of the rocker in said one direction forcamming said arm to said one operative position.

3. The subject matter of claim 2 wherein said arm comprises a flat stripwhich is bent to form said inclined and straight arm sections.

4. The subject matter of claim 1 wherein said element comprises a pin onsaid rocker spaced from and extending substantially parallel to therocker pivotal axis, said straight section extending between said latteraxis and said pin, and the portion of the arm adjacent said one end ofthe straight section being inclined toward said first plane to affordrelief in the arm to accommodate swinging of the latter in saiddirection toward said element under the action of said yieldable means.

5. The subject matter of claim 1 wherein said rocker comprises anelongate platen extending to opposite sides of the rocker pivotal axisand having a generally cylindric surface extending to opposite ends ofthe platen and substantially paralleling the latter axis, and saidhandle means comprises an elongate handle member pivotally mountedintermediate its ends on said support and including a yieldable elementat one end engaging said cylindric surface and movable between oppositeends of the platen by swinging of the handle to rock said rocker inopposite directions.

6. An electric switch, comprising: a support, a rocker pivotally mountedon said support, a pair of switch means mounted on said support and eachincluding a pivotal actuating arm swingable about an axis spaced fromand substantially paralleling the pivotal axis of the rocker, each ofsaid arms extending toward the latter axis and being formed with arelatively short, straight section extending substantially parallel to afirst imaginary plane passing through the latter axis and the pivotalaxis of its respective actuating arm and extending to opposite sides ofa second imaginary plane passing through the rocker pivotal axis normalto the respective first plane, a pair of actuating-arm-engaging elementson said rocker, one of said elements being rotatable into one of saidsecond planes and engageable with one of said straight sections when therocker is rocked in one direction, and the other element being rotatableinto the other second plane and engageable with the other straightsection when the rocker is rocked in the opposite direction forretaining the respective actuating arms in one operative position, saidelements being movable beyond one end of their respective straightsections when the rocker is rocked in the opposite directions, theportions of the respective arms adjacent Vsaid one end of said onestraight section being relieved to accommodate swinging of the armstoward their respective elements to second operative positions when saidelements are located beyond said one end of their'respective straightsections, each of said switch means including yieldable means biasingits actuating arm toward its respective element, and handle means forrocking said rocker in opposite directions.

7. The subject matter of claim 6 wherein said elements comprise a pairof pins on said rocker spaced from and extending substantially parallelto the rocker pivotal axis, the portions of said actuating arms adjacentsaid one end of the straight section being inclined away from therespective pins and forming camming surfaces engageable by the pins forcamming the arms toward their respective one operative position when therocker is rocked.

8. The subject matter of claim 7 wherein said straight section of eachactuating arm extends between the adjacent pin and the pivotal axis ofthe rocker, said inclined portion of each arm inclining toward therespective rst plane.

References Cited inthe tile of this patent UNITED STATES PATENTS2,267,203 'Krieger Dec. 23, 1941 2,369,964 Go Feb. 20, 1945 FOREIGNPATENTS 723,704 Great Britain Feb. 9, 1955

